Conventional methods for producing xerographic reusable media entail coating a small photochromic molecule and a non-photochromic polymer binder to create a thin imaging layer of photochrome and binder on a preformed substrate, such as paper. The resulting media is re-writable and reusable as a result of the reversible coloration-decoloration properties of the photochromic molecule. In the conventional methods of imaging with conventional reusable media, ultraviolet (UV) light is used to color (or write) the photochrome in the media, and visible light and/or elevated temperatures reverses the coloration process, erasing the color of the photochrome within the media.
However, a disadvantage of the conventional reusable media is the length of time that the image is legible on conventional reusable media (i.e., the “image life” of the media). For example, U.S. Pat. No. 7,214,456 discloses a transient document system that has an image life of less than 4 hours under standard office lighting conditions, which may be too short for most applications.
Furthermore, U.S. Pat. No. 3,961,948 discloses an imaging method based upon visible light induced changes in a photochromic imaging layer containing a dispersion of at least one photochromic material in an organic film forming binder. Other known photochromic materials are disclosed in U.S. Pat. No. 4,026,869; U.S. Patent Application Publication No. 2005/0244742, filed Apr. 29, 2004; U.S. Patent Application Publication No. 2005/0244743, filed Apr. 29, 2004; U.S. Patent Application Publication No. 2005/0244744, filed Apr. 29, 2004; U.S. patent application Ser. No. 12/206,136, filed Sep. 8, 2008, the disclosures of which are incorporated by reference in their entireties.
Reusable media comprising other small molecule photochromes have been able to achieve only a slightly longer image life time (3-5 days), when the reusable media was directly imaged and then placed in (or under) a yellow film that serves to filter out the ambient UV light emitted by standard fluorescent office light bulbs (such as described in U.S. Patent Application Publication No. 2008/0311494, and U.S. patent application Ser. No. 12/145,412. However, if this reusable media is not placed under a protective yellow film, the standard image life was only approximately 4 hours, due to a reduction in color contrast resulting from background coloring. Furthermore, another disadvantage is that many consumers do not like the inconvenience of using the protective yellow film. The appropriate components and process aspects of each of the foregoing may be selected for the present disclosure in embodiments thereof, and the entire disclosure of the above-mentioned references are totally incorporated herein by reference.